What is AVAX used for?

Could you kindly explain the utility of AVAX to me? I've heard quite a buzz about it in the cryptosphere, but I'm still hazy on its exact applications. Is it primarily used as a means of exchange, or does it serve some other specific purpose within the blockchain ecosystem? Is it involved in smart contracts or decentralized applications? Also, could you elaborate on how AVAX contributes to the scalability and security of the network it operates on? I'm eager to understand its role in the broader cryptocurrency and finance landscape.